Zero splits



June 9, 1953 F. E. HAMlLrroN ZERO SPL-ITS 2 Sheets-Sheet l F'ledJan. l2, 1949 ATTORNEY APRC' June 9, 1953 F. E. HAMILTON ZERO SPLITS 2 Sheets-Sheet 2 Filed Jan. 12, 1949 lNvENToR FRA/V05 f. HAM/L T0# ATTORNEY Patented June 9, 1953 ZERO SPLITS Francis E. Hamilton, Endicott, N. Y., assigner to International Business Machines Corporation, New York, N. Y., a corporation of New York Application January 12, 1949, Serial No. 70,575

3 Claims.

This invention relates to means for printing data a line at a time on a work sheet. `More particularly, the invention relates to a printing means adapted to print numerical data, one or more numbers on a line. Print units of this kind may be independent or may be associated with manual key controlled calculators or with automatic calculators. `Such automatic calculator may be of the card controlled kind, as exemplied 'by U. S. Patent 2,199,547, or may be any other calculator in which automatic means for reading out numbers are provided.

In printing numbers, it is customary to suppress printing of zeros preceding, i. e., to the left of a first significant digit and to print zeros following, i. e., to the right of the signiilcant digit. It has been recognized, however, that when printing a decimal fraction, it is desirable to print the zeros preceding the first signicant digit as well as the zeros following the signicant digit. U. S.

Patent 2,199,547 suggests doing this by printing zeros to the right of a number preceding the decimal fraction number on the same line. The limitations in this are apparent.

The present invention provides for the printing of zeros preceding a rst signiiicant digit of a number, independently of any other number on the same line. The class of print units to which the invention maybe applied, as an example, provides type carriers which are arrested in differential positions to present different digit types, including types, at a printing line prior to a common printing time. The positioning of the carriers for selection of all but the 0 types is under control of digit reading out or sensing means or other digit selecting means. As for a 0 type it is presented at the printing line only in the absence of selection of any other digit type in the same column or on the same type carrier.

Individual hammers one to each type carrier are provided. These hammers are normally latched by individual latches. At the printing time a common mechanism trips all the latches except those which are latching the hammers associated with the type carriers which have their 0 type at the printing line. Instead, the tripping of those latches is eilected under control of zero splits or carry zero elements which are couplers between adjacent latches. In the prior art the couplers are constructed to carry zeros only to the right or to a lower order from a higher order. For this purpose, the prior art couplers have two possible positions in. one of which they carry zeros to the right and in the other of which they areidle.

(Cl. lOl-93) The present invention provides couplers which comprise centrally pivoted levers mounted to have three distinct positions, one for carrying zeros to the right, another for carrying zeros to the left, and a third in which they are idle. The setting of these levers is by hand.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings: f

Fig. 1 is a vertical section through the print unit.

Fig. 2 shows the drive for the print unit.

Fig. 3 shows the three possible positions of the coupler. y

Fig. 4 is a 4perspective view showing the couplers in relation to adjacent hammer latches.

Except for certain differences Which will be indicated, the printing unit is of the kinddisclosed in prior U. S. Patentsf2,079,4l8, 2,199,547 and 2,042,324. Referring to Fig. 1, the printing unit includes a platen roller 92p. The work sheet is brought around the platen and over a pin-feed wheel 295, then over a cover plate 296. rBehind the platen roller are parallel type carriers 93p.

Each type carrier mounts a column'of eleven type slides 94p bearing types which are, from top to bottom, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0. The types are inverted in order that the recorded characters be in upright position for viewing by an observer when the printed portion of the sheet is on or in front of cover plate 296. Each type carrier is connected at the bottom to a link 91p pivoted at 98p, and connected by a spring 99p to a common bar |0010. Bar |0017 is xed between arms llp fast to a. shaft i021. Connected by links [04p to arms llllp is a restoring bail |031) overlying all the arms 91p.

Fixed to the shaft |021) is an arm |051) which is connected by link [06p to a cam follower llp. The cam follower follows a pair 'of complementary cams |0912 and llllp which are fixed to a cam shaft l I lp. During each revolution of the cam shaft the cams l09p and Illlp oscillate lthe cam follower I0'lp. Upon the counterclockwise movement of follower |011), shaft |0213 and arms IOIp move clockwise. Restoring bar |03p also moves clockwise while the springs 99p force the arms 91p to follow, elevating the type carriers 93:0.

The type carriers may be individually arrested in different positions to present selected types at print position. The arresting means includes ratchet teeth ||9p provided on each type carrier and spaced similarly to the type slides 94p, except for the last, type slide, which has no corresponding tooth ||9p but is presented to printing position when the type carrier rises to its limit. Arranged to coact with the ratchet teeth of each type carrier is a pawl |813 held by armature latch Illp of a magnet PM for engaging the ratchet teeth. When the magnet is energized the latch ||`|p is released from pawl H812 which springs into arresting engagement with a tooth i |933 of a type carrier. There is one such arresting means including a magnet PM for each type carrier.

Magnets PM are energized selectively at the differential times at which'types 9, 8 2, and l are presented to printing position during upward travel of the type carriers. In this way, the type carriers will be arrested with selected types at the printing line.

tions of magnets PM may be used; for example, card sensing circuits and counter readout circuits, as in U. S, Patent 2,199,547. The selection of types may be effected in any other suitable way; it is essential, however, that all the desired types corresponding to the digits of one cr more numbers to be printed on a line be arrested at the printing line before the printing ope..

When a type carrier is arrested, the arm Sip stops and the connected sprint, ssp stretches while the actuating arms |02?) and restoring bail |0313 continue Ato rock clockwise. After the period during which the type ci the print hammers p are tripped and s' the type elements at printing position in ord print the selected data through an ink ribbon upon the work sheet on the platen.

The type hammers 95p are free on shaft 96p and urged into printing action by springs |302). This action is normally restrained 'oy latches |3Ip. Interponents |3211 are pivotf-illy carried by the lower ends of the latches. At reir rear the interponents hook over a bail |3331 fixed to a shaft |3411. A hammer restoring bail Uidp is fixed on the shaftSEp. Shaft lp has xed to it an arm |351) which has a pir-.i and slot connection to a link |3619 pivoted to a bell crank |3771 fixed to the shaft 96p. The bell crank |3712 is connected by a link |38p to an arm |3531 fixed to a pivot shaft [40p which also has fixed to it a cam follower Nip. Cam follower ilHp cooperates with complementary iflp carried. by the cam shaft lllp. During a revolution of the cam shaft the cams |4323 act through the scribed linkage to rock the shafts 98p and |34@ first clockwise and then counterelockiifise. The pin and slot connection between link |3337 and arm |35p permits shaft 55p and restoring bail |44p toA move clockwise before the arm |35@ moves clockwise, so that the bail |4433 may be moved out of the way of the hammers 95p before the bail |3311 moves to the rear for releasing the hammer latches |3|p. Upon the release of the hammer latches from the printing hammers, the springs |3071 drive the printing hammers into printing action. Upon connterclockwise movement of the shaft' 95p, the bail |449 restores the hammers to latched position.

After the printing operation, the restoring bail `|0319 moves down and returns the type carriers 93p to their lower limit. When the type carriers have been restored, the pawls H810 are returned into latching engagement with the latches ilo. The means for effecting the return of the pawls into latching engagement includes a cam.300 on s 4 the cam shaft lllp. 'I'he cam 300 is engaged by a follower 30| which is connected by a link 302 to a lever 303. The lever 303 is urged by a. spring 304e in a counterclockwise direction so as to maintain the follower 30| engaged with the cam 300. The upper end of lever 303 abuts a bail 304 pivoted on a shaft 305 on which the pawls ||8p are loosely mounted. The bail 304 is connected by a link 306 to an armature knock-ofi' bail 301. After the type carriers have been restored, the cam 300 rocks follower 30| counterclockwise, causing the lever 303 to move clockwise for rocking the bail 304 upwardly and causing the bail 301 to move clockwise. The bail 304 thereby restores the pawls ||8p and the bail 301 positively returns the armatures ||`|p into latching engagement with the returned pawls.

Any suitable circuits Y for effecting the differentially timed energiza- When a type carrier 93p rises to its upper limit it presents its zero typeto printing position. As the type carrier rises to its upper limit, a lug 291 on the type carrier moves a pivoted bell crank 208 counterclockwise. A lateral projection 2080 on the bell crank thereupon tilts the associated interponent |3210 out of the path of the bail |3311, so that printing of zero may be suppressed.

It is desired, however, to be able to print zeros to the right of a significant digit; i. e., in orders below the significant digit order, 'in prior art machines, this has been accomplished by couplers, each pivotally mounted on a hammer latch, and having two positions of adjustment. In one position of a coupler, it has no effect on the hammer latch at the right. In an alternative position of the zero-carry lever, it couples its own supporting latch to the hammer latch at the right. An example of such mechanical connection between adjacent hammer latches is the leve;- 232 in Fig. 3 of U. S. Patent 2,199,547. In this way, printing of zeros to the right ot a significant digit has been effected. The present printing unit provides also for printing o! zeros to the left of a significant digit; that is, in orders above the significant digit order. This is desirable when dealing with decimals.

For this purpose, a novel carry-zero lever or coupler 3|0 (Figsl 1, 3 and 4) is provided. This coupler is pivot-ally cari-fied at the upper end of a. hammer latch |3I'p and has three positions in lplace of the conventional two. The coupler is frictionally retained in any of the three positions to which it may be manually adjusted.

Fig. 4 is a perspective view of a pair of adjacent hammer latches Hip, withtheir couplers 3|0 and also shows the front end of the coupler 3|0 at the left of the two latches shown. Since the types are inverted and the printed numbers are read upright from the front of the platen 92p (Fig. l), the denominational order relationship from left to right of the elements shown in Fig. 4 is lower order lever 3 0, intermediate order hammer latch |3 Ip and its lever 3| 0, and higher order latch |3|p and its lever 3|0. With lower order lever 3 0 in position C (also see 3) it is out of the path of movement of the intermediate (next higher) orderflatch |`3|p. If the intermediate `order hammer latch is rocked to trip its type hammer, it will not aiect the lower order hammer latch in position C and printing of zeros in the orders below the intermediate order will not take place. Also, movement of the lower order latch will not affect the intermediate order latch The lever 3|0 is placed in position C to provide a split between numbers. With the intermediate order lever 3|0 in position B, its front lug 3|0a is in the path of the transversely .bent lug |3|a of the higher order. rlhus, if the latch |3110 in the higher order moves forward to trip its hammer, it will eifect similar movement of the intermediate order hammer latch, even if the intermediate order type carrier 93p (Fig. 1) has moved to its upper limit to present at printing position. Irl this way, if the higher order prints a significant digit, zero will be printed in the intermediate (next lower) order. Should the lower order lever SI also be in position B, the movement of the intermediate order latch I 31p will effect movement of the lower order latch. Thus, printing of zeros in one or more orders below a significant digit order may take place. If the lever 3 I 0 in the intermediate order were in position A, which is the position shown in Fig. i of lever 3I0 of the higher order, then its edge 3I0b would be behind the lug I'3Ia of the higher order. Accordingly, forward hammer tripping movement of the intermediate latch Ilp would be communicated. by its lever BID to the higher order latch I3lp. In this way, even if the higher order type carrier moved to zero position, a Zero would be printed if the intermediate order had a signicant digit. By setting successive adjacent levers 3l!) in position A, printing of as many zeros as desired in orders above a signicant digit order may be effected.

It should be noted that if intermediate lever 3 I 0 were in position A, its lug 3Illa would be in the path of lug I3 Ia of the higher order and the edge 3 I 3b of this lever also would be in position to engage the lug I3Ia of the higher order. Thus, if the intermediate order latch is rocked forward, it will move the higher order latch, or if the higher order latch is rocked forward it will move the intermediate order latch.

In short, with a lever 3M! in position C, its supporting latch I'3Ip is unaffected by the latch in the order above and does not aifect the latch in the order below. If the lever 310 is in position B, its supporting latch I 3 Ip is moved if the latch in the order above is moved, so that zero printing in the lower order will be eifected. If the lever SIU is in position A, its supporting latch I3Ip when tripped will trip the latch in the order above and will itself be tripped if the order above is tripped, so that zero will be carried from the lower to the higher or from the higher to the lower of the two orders.

The platen roller 92p (Fig. 1) and the pin-feed wheel 295 are suitably geared together and operated by suitable line spacing means; such as, for example, disclosed in U. S. Patent 2,189,()25.

The printer unit is clutched in for a cycle upon energization of a clutch magnet PRC (Fig. 2) which releases detent 3&5 from a clutch pawl 3 I6. The clutch pawl springs into engagement with a tooth of a driving element 3H and couples the cam shaft I I Ip to the driving element. The driving element is driven by gearing in a gear box 3 I 8, which gearing is actuated by belt-and-pulley connection 3 I 9 from a motor PRM. The clutch magnet will be deenergized shortly after the cam shaft starts a revolution, and detent 3 I 5 thereby will be positioned to retract the clutch pawl 3 I 6 and stop the cam shaft at the end of its revolution. The clutch magnet may be reenergized before the cam shaft completes its revolution, so that the cam shaft may continue uninterruptedly for a second revolution, and so on.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

l. In a print unit having type carriers settable selectively to present significant digit types and 0 types at a printing line to be struck by harnmers, when unlatched, for effecting printing of a number on a work sheet; a row of hammer latches, one for each hammer, mechanism for tripping the latches from hammers for striking signiiicant digit types, and selective mechanism for tripping the latches from hammers for striking zero types, said selective mechanism including zero splits each comprising a centrally pivotally mounted lever mounted upon its supporting latch, one portion of said lever extending in one direction from its pivotal mounting and comprising a generally Ll-shaped portion having a longer side remote from said pivotal mounting and a shorter side, respectively closer to said mounting, another portion of said lever extending in the opposite direction from said pivotal mounting and comprising manually operable means for adjustably rotating said lever to three positions, a lug on another of said latches assesiated with a next higher order extending into the plane of movement of said lever, said lever in one of its three positions engaging said lug with the longer side of the U-shaped portion, said lever in another of its three positions engaging said lug with both the longer and shorter sides of said U-shaped portion and said lever in the third of said three positions removing both the longer and shorter sides of said U-shaped portion from engagement with said lug.

2. A device as in claim 1, said longer side of said U-shaped portion when moved into engagement with said lug comprising means whereby the motion of the latch including said lug produces motion of said zero split lever to thereby impart motion to its supporting latch whereby lower order zeros are printed.

3. A device as in claim 1, the shorter side of the said U-shaped portion when engaged with said lug imparting motion to the latch including said lug whereby higher order zeros are printed.

FRANCIS HAlWILTON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,863,098 Borel June 14, 1932 2,150,218 Gray Mar. 14, 1939 2,199,547 Peirce May 7, 1940 2,387,861 Smith et al Oct. 30, 1945 

